@misc{indiciaec23c3144108a,
  title = {Petroleum and natural gas},
  author = {Ralph Arnold and G. B. Richardson and Chester Wesley Washburne and A.R. Schultz},
  year = {1908},
  doi = {10.3133/b340f},
  url = {https://pubs.usgs.gov/publication/b340F},
  note = {Source identifier: b340F}
}